Photo kiosks are booths containing hardware or software for creating image content. A consumer can, for example, place a picture in the kiosk, have the picture digitized to a digital image, edit the digital image and print the edited image on various forms of paper output. Some photo kiosks provide pre-designed templates into which a consumer can place his own pictures.
Some photo kiosks contain a scanner unit for converting a picture to a digital image. Typically the scanner unit in such a photo kiosk is a flat bed scanner.
Flat bed scanners are used to convert pictures to digital images by digitizing picture colors at sample locations within a fine two-dimensional spatial grid. Such scanners are typically operated by positioning a picture to be scanned on a glass surface of the flat scanner bed, closing the scanner bed cover over the glass surface, and then scanning a region of the scanner bed by means of scanning units located underneath the scanner bed. Flat bed scanners are typically connected to computers and operated using software applications.
A picture to be scanned may occupy only a small part of the full scanner bed area. In order not to scan the full scanner bed area, but rather to scan only a smaller area containing the picture, one can first apply a very low resolution pre-scan to the entire scanner bed area, and then use the pre-scanned digital image to set scanner parameters and select a suitable region of interest surrounding the picture. Such a low-resolution scan can be at a resolution of approximately 24 dots per inch (dpi), which corresponds to approximately 1 pixel per millimeter.
A high resolution scan is costly both in time spent scanning and in scanned image file size. If one were to scan the entire scanner bed area with a high resolution scan, most of the time spent and most of the image data could pertain to the empty part of the scanner bed that does not contain the picture. Moreover if scanner parameters, such as color look-up tables and contrast, are not set properly, the scan may have to be repeated. A pre-scanned digital image can be used to set scanner parameters, and also to select a region of interest that surrounds the picture. By setting the scanner parameters in this way and selecting a region of interest, one ensures that the high resolution scan captures only a sub-area of the entire scanner bed area that contains the picture within it, and that the scanner parameters are properly set before performing the high resolution scan.
In photo kiosks that contain scanners, the scanner unit is typically located inside the kiosk. The consumer may not be able to see the scanner. He may not be able to control the scanner settings, and he may not even be able to view a pre-scanned image. Moreover, even if it were possible to provide such control, it would only serve to complicate the operation of a photo kiosk, thereby frustrating and distancing potential consumers who may have very little or no experience with scanner devices.